21523305134 has 8 divisors (see below), whose sum is σ = 32321358288. Its totient is φ = 10749519040.

The previous prime is 21523305119. The next prime is 21523305137. The reversal of 21523305134 is 43150332512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21523305097 and 21523305106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21523305137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6064547 + ... + 6068094.

It is an arithmetic number, because the mean of its divisors is an integer number (4040169786).

Almost surely, 2^21523305134 is an apocalyptic number.

21523305134 is a deficient number, since it is larger than the sum of its proper divisors (10798053154).

21523305134 is a wasteful number, since it uses less digits than its factorization.

21523305134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12133530.

The product of its (nonzero) digits is 10800, while the sum is 29.

Adding to 21523305134 its reverse (43150332512), we get a palindrome (64673637646).

The spelling of 21523305134 in words is "twenty-one billion, five hundred twenty-three million, three hundred five thousand, one hundred thirty-four".